Docker Crash Course #10 - Volumes

Introduction

In this tutorial, you'll learn how to use Docker volumes to enable a "live preview" experience while developing applications. Docker volumes are essential for persisting data and sharing files between your host and containers, making your development process smoother and more efficient.

Step 1: Understanding Docker Volumes

• Docker volumes are stored outside the container's filesystem and persist even when containers are stopped or removed.
• They allow you to share data between containers and your local machine, which is crucial for a live development environment.
• Benefits of using volumes:
  • Data persistence
  • Improved performance
  • Ease of data sharing

Step 2: Creating a Docker Volume

1. Open your terminal.
2. Use the following command to create a new volume:

   docker volume create my-volume
   

3. Verify the volume creation by listing all volumes:

   docker volume ls
   

Step 3: Using the Volume in a Docker Container

1. Run a Docker container and mount the volume:

   docker run -d -v my-volume:/app --name my-container my-image
   

   • -d runs the container in detached mode.
   • -v specifies the volume to mount (my-volume) and the target path inside the container (/app).

Step 4: Inspecting the Volume

• To see more details about your volume, use:

  docker volume inspect my-volume
  

• This command provides information such as the mount point on the host and the container it's linked to.

Step 5: Using Bind Mounts for Live Development

• For a live preview experience, you can use bind mounts instead of volumes. This allows you to directly map a folder from your local machine to the container.

1. Run a container with a bind mount:

   docker run -d -v /path/to/local/folder:/app --name my-container my-image
   

   • Replace /path/to/local/folder with the actual path on your machine.

Step 6: Making Changes and Seeing Live Updates

• After setting up the bind mount, make changes to files in your local folder.
• The changes will automatically reflect in the running container, enabling a seamless development experience.

Tips for Effective Use of Docker Volumes

• Regularly clean up unused volumes to save space using:

  docker volume prune
  

• Use descriptive names for your volumes to avoid confusion, especially when working on multiple projects.

Conclusion

Docker volumes and bind mounts are powerful tools for improving your development workflow. By following the steps outlined in this tutorial, you can set up a live preview environment that enhances your productivity. Explore further by integrating Docker with your chosen development stack and consider reviewing Docker documentation for advanced usage.